As a last resort, you could try Ebay Express http://www.express.ebay.com/ , which is more like a marketplace, rather than an auction house. Enter 'Tommy Bahama tie' in their search box, and about 100 ties, in various colors, will appear, priced in the $20-30 range (including shipping)

These will have some tropical and hula patterns, but maybe not specifically tiki.

You might ask Dawn, she has sewing talent and could make one and she has personally designed Tiki fabrics.
http://www.etsy.com/shop/sophistatiki_________________ "Oh waiter, another cocktail please!!!"